[molpro-user] F12 methods

[Christian Evenhuis]

I am trying out the new F12 methods but I am not having much luck.

1. if I use the VNZ-F12 basis sets I get the following error:
		1PROGRAM * CCSD (Closed-shell coupled cluster)     Authors: C.  
Hampel, H.-J. Werner, 1991, M. Deegan, P.J. Knowles, 1992
                CCSD-F12 implementation by  H.-J. Werner, 2007
                Density fitting integral evaluation by F. R. Manby,  
2003,2007
                Cannot find default basis VDZ-F12 for atom O

2. The MP2-F12 energies for AVNZ series is
	AVDZ	-152.71791751
	AVTZ	-152.73109952
	AVQZ 	-149.60581350
The contribution to the energy are listed after the input deck.

3.  For CCSD(T)-F12 / AVNZ  I get the following error
              ? Warning
              ? Encountered below-occupied eigenvalues in virtual  
block. This may indicate serious deficiencies in the orbital or
                 JKfit-basis sets (basis_exch). Offending values will  
be ignored, but PT2 is ill-conditioned!
              ? The problem occurs in f12_common/Mp2Singles()
              FockProj BlockDiagonalize() eigenvalues:  
(norb=                   314 )
              E(Occ):   -20.5969651851479       -20.5474946885548
               -1.38499649063043       -1.33164908493971       
-0.749957814812005
              -0.701772636068004      -0.612407775875517       
-0.558616202902750
              -0.531801726963611      -0.483450539393589

     Changing to RI_BASIS=AVTZ/ORBITAL helped a little but did not  
resolve the issue

Thanks,

Chris Evenhuis


INPUT DECK:

*** water dimer
geomtyp=xyz

geometry={noorient;
6
lp
O   0.0640488861  -1.5542001572   0.0000000000
H  -0.0275603110  -0.6109761929   0.0000000000
H  -0.8291328873  -1.8994223998   0.0000000000
O  -0.0539423286   1.4751039841   0.0000000000
H   0.3402097464   1.8881478835   0.7547208224
H   0.3402097464   1.8881478835  -0.7547208224
}

basis=BASIS
{hf
  accu,14
}

{METHOD-F12
}


CONTRIBUTION TO MP2-F12 AVDZ ENERGY

MP2 singlet pair energy:              -0.369580050529
MP2 triplet pair energy:              -0.202617031749
MP2 correlation energy:               -0.572197082278
MP2 total energy:                   -152.712931523922

SCS-MP2 correlation energy:           -0.569568880390   (PS=   
1.200000  PT=  0.333333)
SCS-MP2 total energy:               -152.710303322034

Norm of t2 vector:      0.35747963      P-energy:    -0.57219708

  Reference energy                   -152.138817231768
  F12 singles correction               -0.001917209877

  F12 singles corrections added to reference energy

  New reference energy               -152.140734441644

  MP2-F12 singlet correction            1.955823920706
  MP2-F12 triplet correction            1.151294106399
  MP2-F12 total correction              3.107118027105

  F12 corrections for ansatz F12/3C(FIX) added to MP2 energy

  MP2-F12/3C(FIX) singlet pair ener     1.586243870177
  MP2-F12/3C(FIX) triplet pair ener     0.948677074650
  MP2-F12/3C(FIX) correlation energ     2.534920944827

!MP2-F12/3C(FIX) Energy             -149.605813496817